SELECT 
  cscart_cp_blog_category_descriptions.category, 
  cscart_cp_blog_category_descriptions.description, 
  cscart_cp_blog_category_descriptions.category_id 
FROM 
  cscart_cp_blog_post_categories 
  LEFT JOIN cscart_cp_blog_categories ON cscart_cp_blog_categories.category_id = cscart_cp_blog_post_categories.category_id 
  LEFT JOIN cscart_cp_blog_category_descriptions ON cscart_cp_blog_category_descriptions.category_id = cscart_cp_blog_post_categories.category_id 
WHERE 
  1 
  AND cscart_cp_blog_categories.status IN ('A') 
  AND cscart_cp_blog_categories.company_id = 1 
  AND cscart_cp_blog_category_descriptions.lang_code = 'ru' 
  AND cscart_cp_blog_post_categories.post_id = 12

Query time 0.00069

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_cp_blog_post_categories",
      "access_type": "ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["post_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100,
      "using_index": true
    },
    "table": {
      "table_name": "cscart_cp_blog_categories",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["category_id"],
      "ref": [
        "orbit_cscart_orbit_cscart.cscart_cp_blog_post_categories.category_id"
      ],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "cscart_cp_blog_categories.company_id = 1 and cscart_cp_blog_categories.`status` = 'A'"
    },
    "table": {
      "table_name": "cscart_cp_blog_category_descriptions",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["category_id", "lang_code"],
      "ref": [
        "orbit_cscart_orbit_cscart.cscart_cp_blog_post_categories.category_id",
        "const"
      ],
      "rows": 1,
      "filtered": 100,
      "index_condition": "cscart_cp_blog_category_descriptions.lang_code = 'ru'"
    }
  }
}